Dealer tech clueless on GT4 alignment...need help.
12-26-2015, 04:09 PM
#31
If you are going the shim route, you are going to need toe arms and adjustable caster pucks. Just call BGB, they will get you everything you need.
The lower control arm is angled forward, so if you make it longer (with shims), it pushes the wheel further forward into the wheel well. The caster will improve a bit, but the tire will rub. To fix this, you need an adjustable caster puck which will give you another degree of freedom to get the lower control arm angled a bit further back.
My CAD wings have been clipped, so here is a quick power point block diagram of what I mean...not to scale
The lower control arm is angled forward, so if you make it longer (with shims), it pushes the wheel further forward into the wheel well. The caster will improve a bit, but the tire will rub. To fix this, you need an adjustable caster puck which will give you another degree of freedom to get the lower control arm angled a bit further back.
My CAD wings have been clipped, so here is a quick power point block diagram of what I mean...not to scale
12-26-2015, 04:14 PM
#32
If you are going the shim route, you are going to need toe arms and adjustable caster pucks. Just call BGB, they will get you everything you need.
The lower control arm is angled forward, so if you make it longer (with shims), it pushes the wheel further forward into the wheel well. The caster will improve a bit, but the tire will rub. To fix this, you need an adjustable caster puck which will give you another degree of freedom to get the lower control arm angled a bit further back.
My CAD wings have been clipped, so here is a quick power point block diagram of what I mean...not to scale
Attachment 1004902
The lower control arm is angled forward, so if you make it longer (with shims), it pushes the wheel further forward into the wheel well. The caster will improve a bit, but the tire will rub. To fix this, you need an adjustable caster puck which will give you another degree of freedom to get the lower control arm angled a bit further back.
My CAD wings have been clipped, so here is a quick power point block diagram of what I mean...not to scale
Attachment 1004902
+1
12-26-2015, 10:18 PM
#33
Burning Brakes
What about using adjustable compression links? Which are more preferable?
http://www.teambgb.com/Tarett-RSR-Te...tarett_tcl.htm
http://www.teambgb.com/Tarett-RSR-Te...tarett_tcl.htm
12-26-2015, 11:48 PM
#34
That's an even better option than the pucks (145ea) - but twice as much (305ea).
Positive is longer range of adjustability (I think, tarret would know better....) and perfect precision. Downside is the spherical that will eventually rattle. But - having no experience with how long, or how this will feel, I don't see this as a downside.
Positive is longer range of adjustability (I think, tarret would know better....) and perfect precision. Downside is the spherical that will eventually rattle. But - having no experience with how long, or how this will feel, I don't see this as a downside.
Last edited by ShakeNBake; 12-27-2015 at 01:23 AM.
12-27-2015, 03:02 AM
#35
Very interesting topic.
May I ask what tyre you have?
I believe the difference between Dunlop and Michelin plays a part as well.
May I ask what tyre you have?
I believe the difference between Dunlop and Michelin plays a part as well.
12-27-2015, 11:38 AM
#36
No, unlike the GT3's in the past where rotating the strut top to different screw holes allowed you to get higher negative camber, you cannot do that on the GT4. BTW, love your drawings showing the added castor. Rotating the strut on the old GT3 didn't add any caster but it also didn't widen the track width. Most folks did both. Never thought to change the thrust arm bushing though. Very clever.
12-27-2015, 06:38 PM
#37
One thing nobody is mentioning is ride height. Lowering the height will add positive camber. Maybe that is the missing variable. Dealer techs work flat rate btw, meaning a flat fee for the quoted job, and most don't know thier *** from thier elbow IMO.
12-27-2015, 09:42 PM
#38
Sorry to hear about your dealer experience. Looks like you're in CT. If Fairfield isn't too far away from you, I highly recommend Porsche of Fairfield. If you'd like me to give you their lead tech's info feel free to pm me. Only person I trust with my cars and incoming GT4.
Hope everything gets sorted out!
Hope everything gets sorted out!
12-27-2015, 09:59 PM
#39
Rennlist Member
Originally Posted by steve0827
Sorry to hear about your dealer experience. Looks like you're in CT. If Fairfield isn't too far away from you, I highly recommend Porsche of Fairfield. If you'd like me to give you their lead tech's info feel free to pm me. Only person I trust with my cars and incoming GT4.
Hope everything gets sorted out!
Hope everything gets sorted out!
12-27-2015, 10:04 PM
#40
12-30-2015, 10:51 AM
#41
Burning Brakes
Thread Starter
Wallingford sorted it out in the end but the lesson here is don't use the dealer for track alignments.
12-30-2015, 02:35 PM
#42
Instructor
If you are going the shim route, you are going to need toe arms and adjustable caster pucks. Just call BGB, they will get you everything you need.
The lower control arm is angled forward, so if you make it longer (with shims), it pushes the wheel further forward into the wheel well. The caster will improve a bit, but the tire will rub. To fix this, you need an adjustable caster puck which will give you another degree of freedom to get the lower control arm angled a bit further back.
My CAD wings have been clipped, so here is a quick power point block diagram of what I mean...not to scale
Attachment 1004902
The lower control arm is angled forward, so if you make it longer (with shims), it pushes the wheel further forward into the wheel well. The caster will improve a bit, but the tire will rub. To fix this, you need an adjustable caster puck which will give you another degree of freedom to get the lower control arm angled a bit further back.
My CAD wings have been clipped, so here is a quick power point block diagram of what I mean...not to scale
Attachment 1004902
08-31-2016, 02:30 PM
#43
I just took my car to the dealer and had the same alignment as OP. I doubt that both our cars were built incorrectly to the same spec so I feel the issue is something simple like a missing shim. My car has one shim that is about 4~5mm thick. Someone here posted that the car should come with two shims. Does this mean total of 8~10mm of shims? I wonder how many or how large the shims were on the cars that were able to go to -2...
08-31-2016, 09:42 PM
#45
If you are going the shim route, you are going to need toe arms and adjustable caster pucks. Just call BGB, they will get you everything you need.
The lower control arm is angled forward, so if you make it longer (with shims), it pushes the wheel further forward into the wheel well. The caster will improve a bit, but the tire will rub. To fix this, you need an adjustable caster puck which will give you another degree of freedom to get the lower control arm angled a bit further back.
My CAD wings have been clipped, so here is a quick power point block diagram of what I mean...not to scale
Attachment 1004902
The lower control arm is angled forward, so if you make it longer (with shims), it pushes the wheel further forward into the wheel well. The caster will improve a bit, but the tire will rub. To fix this, you need an adjustable caster puck which will give you another degree of freedom to get the lower control arm angled a bit further back.
My CAD wings have been clipped, so here is a quick power point block diagram of what I mean...not to scale
Attachment 1004902
Very helpful diagram. Well done and thank you.